feat(intentions): Phase 7 — if-then rules for task / time / triage triggers

Small if-then automation layer. Rules persist in SQLite; the runner
lives on the frontend and binds to the Phase 6 event bus so the rule
pipeline reuses the same delivery primitives (timer events, TTS,
Tasks navigation).

Storage:
- Migration v12 adds implementation_rules (id, enabled, trigger_kind,
  trigger_value, actions_json, last_fired_key, created_at,
  updated_at) with enabled+trigger_kind index for the runner's hot
  path.
- CRUD helpers: insert / list / get / set-enabled / mark-fired /
  delete, plus a round-trip test.

Commands (all main-window-guarded via ensure_main_window):
- list_implementation_rules
- create_implementation_rule — validates HH:MM, checks the target
  task exists at save time for surface-task actions, caps
  speak-line at 240 chars, pins v1 timers to 5 minutes.
- set_implementation_rule_enabled
- mark_implementation_rule_fired — main-thread idempotency shim so
  the runner can atomically claim a fire.
- delete_implementation_rule

Runner (implementationIntentions.svelte.ts):
- Subscribes to kon:task-completed and kon:morning-triage-finished
  (MorningTriageModal now emits on all three exit paths — empty,
  skipped, picked — so skip counts as finishing).
- 30 s poll for time-of-day rules, plus an immediate check on startup
  so a rule whose time has already passed today catches up once.
- Idempotency via last_fired_key composed as YYYY-MM-DD@HH:MM for
  time rules; new time rules whose HH:MM has already passed today
  are pre-seeded so they don't fire retroactively on save.
- Rules are paused when Nudges "Mute for now" is on — a hard mute
  stops all rule delivery in addition to OS notifications.
- Stale-task safety: if a surface-task action's target has been
  deleted, the runner opens Tasks and warns clearly rather than
  pretending to surface something that's gone.

Editor (ImplementationRulesEditor.svelte):
- Lives in Settings under a new "If-then rules" accordion section.
- `If` picker: time of day (with time input), a task completes,
  morning triage finishes.
- `Then` composer: optional surface (inbox / today / all tasks /
  specific task), optional 5-min timer, optional speak-aloud line.
- Saved rules list with enable toggle + delete.

Rules table integration for Phase 10b rename sweep: add
implementation_rules to the kon.db → corbie.db migration shim when
that phase lands.

Gates: fmt, clippy -D warnings, cargo test 265/0, svelte-check
0/0, npm build green. Pre-existing Vite chunk warning on sounds.ts
is unrelated to Phase 7.

src/lib/components/ImplementationRulesEditor.svelte

@@ -0,0 +1,266 @@
+<script lang="ts">
+  // @ts-nocheck
+  import { onMount } from "svelte";
+  import { Trash2 } from "lucide-svelte";
+  import Toggle from "$lib/components/Toggle.svelte";
+  import { tasks } from "$lib/stores/page.svelte.js";
+  import { toasts } from "$lib/stores/toasts.svelte.js";
+  import {
+    createImplementationRule,
+    deleteImplementationRule,
+    implementationRules,
+    initialLastFiredKeyForTimeRule,
+    loadImplementationRules,
+    ruleSummary,
+    setImplementationRuleEnabled,
+  } from "$lib/stores/implementationIntentions.svelte.ts";
+
+  let loading = $state(false);
+  let saving = $state(false);
+  let error = $state("");
+
+  let triggerKind = $state("time_of_day");
+  let triggerTime = $state("09:00");
+  let surfaceEnabled = $state(true);
+  let surfaceTarget = $state("inbox");
+  let surfaceTaskId = $state("");
+  let startTimer = $state(false);
+  let speakLine = $state("");
+
+  let activeTasks = $derived(tasks.filter((task) => !task.done && !task.parentTaskId));
+
+  onMount(() => {
+    loading = true;
+    loadImplementationRules(true)
+      .catch((err) => { error = String(err); })
+      .finally(() => { loading = false; });
+  });
+
+  function triggerValue() {
+    return triggerKind === "time_of_day" ? triggerTime : "";
+  }
+
+  function builtActions() {
+    const actions = [];
+    if (surfaceEnabled) {
+      actions.push({
+        kind: "surface",
+        target: surfaceTarget,
+        taskId: surfaceTarget === "task" ? surfaceTaskId : null,
+        label: surfaceTarget === "task"
+          ? activeTasks.find((task) => task.id === surfaceTaskId)?.text ?? "Task"
+          : null,
+      });
+    }
+    if (startTimer) {
+      const selectedTask = activeTasks.find((task) => task.id === surfaceTaskId);
+      actions.push({
+        kind: "start_timer",
+        seconds: 300,
+        taskId: surfaceTarget === "task" ? surfaceTaskId : null,
+        label: selectedTask?.text ?? "5-minute timer",
+      });
+    }
+    if (speakLine.trim()) {
+      actions.push({ kind: "speak_line", text: speakLine.trim() });
+    }
+    return actions;
+  }
+
+  function canSave() {
+    if (saving) return false;
+    if (triggerKind === "time_of_day" && !/^\d{2}:\d{2}$/.test(triggerTime)) return false;
+    if (surfaceEnabled && surfaceTarget === "task" && !surfaceTaskId) return false;
+    return builtActions().length > 0;
+  }
+
+  async function saveRule() {
+    if (!canSave()) return;
+    saving = true;
+    error = "";
+    try {
+      await createImplementationRule({
+        enabled: true,
+        triggerKind,
+        triggerValue: triggerValue(),
+        actions: builtActions(),
+        lastFiredKey: triggerKind === "time_of_day"
+          ? initialLastFiredKeyForTimeRule(triggerTime)
+          : null,
+      });
+      toasts.success("Rule saved");
+      triggerKind = "time_of_day";
+      triggerTime = "09:00";
+      surfaceEnabled = true;
+      surfaceTarget = "inbox";
+      surfaceTaskId = "";
+      startTimer = false;
+      speakLine = "";
+    } catch (err) {
+      error = String(err);
+    } finally {
+      saving = false;
+    }
+  }
+
+  async function toggleRule(rule, enabled) {
+    try {
+      await setImplementationRuleEnabled(rule.id, enabled);
+    } catch (err) {
+      toasts.warn("Could not update rule", String(err));
+    }
+  }
+
+  async function removeRule(rule) {
+    try {
+      await deleteImplementationRule(rule.id);
+    } catch (err) {
+      toasts.warn("Could not delete rule", String(err));
+    }
+  }
+</script>
+
+<div class="space-y-5">
+  <div>
+    <p class="text-[11px] text-text-tertiary mb-4">
+      Build simple if-then rules. They respect Mute for now in Nudges, and everything stays local.
+    </p>
+
+    <div class="rounded-lg border border-border-subtle bg-bg-input p-4">
+      <div class="grid grid-cols-1 md:grid-cols-[120px_1fr] gap-3 items-start">
+        <p class="text-[10px] font-medium text-text-tertiary uppercase tracking-wider pt-2">If</p>
+        <div class="flex flex-wrap gap-2">
+          <select
+            class="bg-bg border border-border rounded-lg px-3 py-2 text-[12px] text-text focus:border-accent focus:outline-none"
+            bind:value={triggerKind}
+          >
+            <option value="time_of_day">time of day</option>
+            <option value="task_completed">a task completes</option>
+            <option value="morning_triage_finished">morning triage finishes</option>
+          </select>
+          {#if triggerKind === "time_of_day"}
+            <input
+              type="time"
+              class="bg-bg border border-border rounded-lg px-3 py-2 text-[12px] text-text focus:border-accent focus:outline-none"
+              bind:value={triggerTime}
+            />
+          {/if}
+        </div>
+
+        <p class="text-[10px] font-medium text-text-tertiary uppercase tracking-wider pt-2">Then</p>
+        <div class="space-y-3">
+          <div class="flex flex-col gap-2">
+            <Toggle
+              bind:checked={surfaceEnabled}
+              label="Surface a list or task"
+              description="Open Tasks and put the chosen item back in view."
+            />
+            {#if surfaceEnabled}
+              <div class="flex flex-wrap gap-2 pl-1">
+                <select
+                  class="bg-bg border border-border rounded-lg px-3 py-2 text-[12px] text-text focus:border-accent focus:outline-none"
+                  bind:value={surfaceTarget}
+                >
+                  <option value="inbox">Inbox</option>
+                  <option value="today">Today</option>
+                  <option value="tasks">All tasks</option>
+                  <option value="task">Specific task</option>
+                </select>
+                {#if surfaceTarget === "task"}
+                  <select
+                    class="min-w-[220px] bg-bg border border-border rounded-lg px-3 py-2 text-[12px] text-text focus:border-accent focus:outline-none"
+                    bind:value={surfaceTaskId}
+                  >
+                    <option value="">Choose task…</option>
+                    {#each activeTasks as task (task.id)}
+                      <option value={task.id}>{task.text}</option>
+                    {/each}
+                  </select>
+                {/if}
+              </div>
+            {/if}
+          </div>
+
+          <Toggle
+            bind:checked={startTimer}
+            label="Start a 5-minute timer"
+            description="Use the same focus timer as micro-steps."
+          />
+
+          <div>
+            <label for="rule-speak-line" class="block text-[10px] font-medium text-text-tertiary uppercase tracking-wider mb-2">
+              Speak aloud
+            </label>
+            <input
+              id="rule-speak-line"
+              type="text"
+              maxlength="240"
+              class="w-full bg-bg border border-border rounded-lg px-3 py-2 text-[12px] text-text placeholder:text-text-tertiary focus:border-accent focus:outline-none"
+              placeholder="Optional line, e.g. time to plan the day"
+              bind:value={speakLine}
+            />
+          </div>
+        </div>
+      </div>
+
+      {#if error}
+        <p class="text-[11px] text-danger mt-3">{error}</p>
+      {/if}
+
+      <div class="flex justify-end mt-4">
+        <button
+          type="button"
+          class="px-4 py-2 rounded-lg text-[12px] font-medium
+            {canSave()
+              ? 'bg-accent text-bg hover:bg-accent-hover'
+              : 'bg-bg-elevated text-text-tertiary cursor-not-allowed'}"
+          disabled={!canSave()}
+          onclick={saveRule}
+        >
+          {saving ? "Saving…" : "Save rule"}
+        </button>
+      </div>
+    </div>
+  </div>
+
+  <div>
+    <p class="text-[10px] font-medium text-text-tertiary uppercase tracking-wider mb-2">Saved rules</p>
+    {#if loading}
+      <p class="text-[11px] text-text-tertiary">Loading…</p>
+    {:else if implementationRules.length === 0}
+      <p class="text-[11px] text-text-tertiary italic">No rules yet.</p>
+    {:else}
+      <div class="space-y-2">
+        {#each implementationRules as rule (rule.id)}
+          <div class="flex items-center gap-3 rounded-lg border border-border-subtle bg-bg-input px-3 py-2">
+            <button
+              class="relative w-[34px] min-w-[34px] h-[20px] rounded-full flex-shrink-0
+                {rule.enabled ? 'bg-accent' : 'bg-bg-elevated'}"
+              role="switch"
+              aria-checked={rule.enabled}
+              aria-label={rule.enabled ? 'Disable rule' : 'Enable rule'}
+              onclick={() => toggleRule(rule, !rule.enabled)}
+            >
+              <span
+                class="absolute top-[3px] left-[3px] w-3.5 h-3.5 rounded-full bg-white shadow-sm
+                  {rule.enabled ? 'translate-x-[14px]' : 'translate-x-0'}"
+                style="transition: transform var(--duration-ui)"
+              ></span>
+            </button>
+            <p class="flex-1 min-w-0 text-[12px] text-text-secondary leading-snug">
+              {ruleSummary(rule)}
+            </p>
+            <button
+              class="text-text-tertiary hover:text-danger"
+              aria-label="Delete rule"
+              title="Delete rule"
+              onclick={() => removeRule(rule)}
+            >
+              <Trash2 size={14} aria-hidden="true" />
+            </button>
+          </div>
+        {/each}
+      </div>
+    {/if}
+  </div>
+</div>